This invention relates to a light weight extruded heddle support bar for use in a heddle frame assembly on a loom. The heddle support bar of the invention is utilized in connection with the heddle frame assembly on a loom to provide supporting surfaces for supporting heddles within the frame. The heddle frame includes a top frame slat and a bottom frame slat which are spaced apart in the frame by a pair of side frame members. Heddle bars are provided for each of the frame slats, that is, the upper and the lower frame slats for supporting heddles within the frame assembly. The heddles include eyes through which warp threads are threaded.
In the loom, the heddle frame raises and lowers the warp ends to create a shed through which the warp yarn is inserted during weaving. In lifting the warp threads during the shedding motion the heddle frame undergoes forces in a vertical direction while moving the warp ends to form a shed. This produces a bending moment on the frame slat and also the heddle bar.
As the speeds at which the looms are driven increases the inertia loading on the heddle frames and the heddle bars during shedding is greatly increased. Since the inertia forces are dependent upon the mass of the heddle frame assembly, there has been a great need to provide light weight frame members for the heddle frame assembly without sacrificing structural integrity. As noted, during the shedding motion the shedding frame assembly reciprocates vertically in rapid strokes which increase as the operating speeds of the loom increase. Therefore, the provision of a light weight component for the heddle bar is a problem to which considerable attention need be given.
Considerable progress has been made in this area as represented by the disclosure in U.S. Pat. No. 4,633,916 issued Jan. 6, 1987 to John L. Rast, commonly owned by the assignee of the instant application. This patent discloses a light weight shed resistant frame slat with means for supporting a heddle bar at one edge. In the slat disclosed in this patent, two ledges form a mounting slot for the heddle bar. The heddle bar in this patent is a carbon fiber pultrusion which is affixed in the mounting slot by means of an epoxy glue or the like. Since the heddle bar is bonded in the supporting slot it is very difficult, if not impossible, to replace the heddle bar when it becomes damaged or worn.